1. Field of the Invention
This invention relates to a system for audibly recognizing a received signal aurally unclassifiable because it is too short or too long in its time duration and/or its frequency band is too narrow or too wide. Signals of such types are conventionally received from various sensors such as infiltration radars, seismic exploration sensors, medical diagnostic apparatus, etc.. The present invention is a simplification of that described and claimed in applicant's copending application Ser. No. 505,556, filed Sept. 13, 1974, entitled "System for Audibly Recognizing an Aurally Unclassifiable Signal," and assigned to the same assignee as the present application. The present invention is suitable for use particularly when it is desired to recognize a single signal, the waveform of which occupies a relatively narrow frequency band and whose frequency location is time-variable. The present invention permits the use of relatively simple and low-cost apparatus.
2. Description of the Prior Art
No prior art apparatus similar or equivalent to that of the present invention is known although there have been proposed certain computer-oriented algorithms which can be used to perform the detection and classification of received signals. However, such methods require lengthy computer statistical learning and classification processing. As a result, real-time signal processing is neither possible with a single computer nor economical with multiple paralleled computers.
The system of the present invention may be used to invoke the ear-brain for performing the functions of learning, detection, and subsequent classification of aurally unclassifiable signals, both economically and in real-time.